This invention relates to saw chain of the type that is used on power-driven portable chain saws. The invention more particularly concerns a saw chain of this description which exhibits when operated on a chain saw improved anti-kickback characteristics.
The usual chain saw includes a portable frame with handle, mounting a motor which powers the chain saw. Extending outwardly from the frame and motor unit is an elongate bar terminating in what is known as a nose. Saw chain trained over a power-driven sprocket in the motor and frame unit extends from such sprocket along opposite margins of the bar and around the nose of the bar. In the usual chain saw, the saw chain travels away from the operator where such extends along the top margin of the bar, and toward the operator where said extends along the bottom margin of the bar.
Chain saws of the above general description are widely used throughout the world, and generally are recognized as efficient, practical, and convenient cutting instrumentalities. However, as might be expected with any power-driven device, certain problem areas have arisen, and one which has received considerable attention with increasing concerns about safety is what is referred to as kickback when operating the chain saw under certain conditions. As generally understood today, kickback refers to the tendency of the bar in a chain saw to be thrown upwardly and rearwardly toward the operator by reason of the saw chain in the chain saw having its movement abruptly decelerated or stopped during operation of the chain saw.
A general object of this invention is to provide an improved saw chain which exhibits substantially reduced tendency to produce dangerous kickback when operated on a chain saw.
A further object is to provide such saw chain which retains the ability to cut wood efficiently and fast.
Another object is to provide a saw chain of the above general description which may be manufactured without extensive modification in many of the components in the saw chain.
Yet a further object of the invention is the provision of an anti-kickback saw chain which relies on the depth gauge of a cutter link and means located rearwardly in the cutter link from the cutting edge of the cutter portion of the link as correcting means inhibiting penetration of the cutter portion under conditions that with conventional chain would result in kickback.